Posted
by
Soulskillon Friday September 09, 2011 @12:15PM
from the if-it's-worth-doing-it's-worth-doing-with-lasers dept.

arisvega writes with this quote from the BBC:
"The UK company AWE and the Rutherford Appleton Laboratory have now joined with [the National Ignition Facility in the U.S.] to help make laser fusion a viable commercial energy source. ... Part of the problem has been that the technical ability to reach 'breakeven' — the point at which more energy is produced than is consumed — has always seemed distant. Detractors of the idea have asserted that 'fusion energy is 50 years away, no matter what year you ask,' said David Willetts, the UK's science minister. 'I think that what's going on both in the UK and in the US shows that we are now making significant progress on this technology,' he said. 'It can't any longer be dismissed as something on the far distant horizon.'"

Do you think it is powered by magic? The containment vessel would become radioactive waste.

Helium ain't exactly pollution. We could use more of it, and if we do ever get enough we can just let it out and it will escape into space.

But yea, I am fairly sure the mythical 100% hydrogen method of fusion might not see the light of day, but that is what they are aiming at. A hybrid of fusion and fission is probably our best bet though. Hell it works well enough for the hydrogen bomb and the sun.

Maybe. Will it need a containment vessel? If so, is it massive? Can it be foil? What's the half-life of the isotopes produced, if any? What do they degenerate to? Do you know? Are you a researcher? Are you current with the state of laser fusion technology?

Why do you think there would be no radiation or pollution?
Do you think it is powered by magic? The containment vessel would become radioactive waste.

Yes, the fusion reactions, based on the fuel being used, will create toxic radiation requiring sophisticated containment vessels that need careful handing. However, the problem with fission waste - it has a half-life of thousands of years - doesn't exist for the fusion vessels. That type of radiation decays very quickly. In fact, it may even be shorter than the working lifespan of the containment wall itself.

"The UK company AWE and the Rutherford Appleton Laboratory have now joined with [the DOD funded National Ignition Facility in the U.S.] to help make laser fusion part of their nuclear weapons testing program as well.

Seeing as the UK buys all its nuclear bombs from the US anyway, and currently only stocks missiles of a single type (Trident), and has little stomach for replacing them with anything substantially different (there's a big enough ruckus about building new submarines to carry the missiles we've already got), I can't see that being a huge motivator for the UK. What use we'd have for laser-triggered fusion bombs I don't know.

The promise of clean, cheap, not-foreign-dependant energy is probably enough to pull in

We buy the missiles from the US, not the bombs. Though the design may well be US-derived - once we'd tested our own hydrogen bomb, thus proving we could do it, the Americans gave us access to their designs which were further developed and more suitable for deployment.

AWE isn't exactly a "company" either... their full name is the Atomic Weapons Establishment, which should provide some clue as to why they may be interested in this.

By your own link the National Ignition Facility does nuclear weapons maintenance, not nuclear weapons testing.

Weapons maintenance has to do with ensuring that existing nuclear weapons don't leak, explode or otherwise freak out as the components age, and with more deeply understanding just how radioactive material behaves in situations like that of building and storing a bomb; it has little or nothing to do with making new weapons, at least not inherently.

Maintenance requires testing. You need to know that these bombs will work after all these years in testing. Since you can't set off one to test that you must simulate the conditions as best as can be done.

The whole purpose of the NIF facility is to explore the physics of what happens at extreme pressures and temperatures.

That has little to do with maintenance and everything to do with design. Calling it "maintenance" is pure PR. Sure, you could say, "we want to see what will happen to these bombs if we were to detonate them after their tritium has broken down to X degree", or whatnot, but that's about as close as you can get. In reality, it's about maintaining and expanding our knowledge for designing rel

Maybe so. It's also possible that calling it "pure PR" is purely a conspiracy theory. I'm not saying that your statement is irrational or implausible in the least; I'm just saying that going directly against what the NIF itself claims to be doing obviously requires some sources.

The sources are in the article you yourself cited. In fact, in the very same sentence it says "maintenance", it also says "design", and throughout the rest of the article they talk about how it's useful for design.

It's a bit more subtle than what you think the word "maintenance" means in this case:

Hydrogen bombs utilize tritium (2neutrons 1 proton). Unfortunately, tritum has a 13 year half-life (When did the cold war end?), after which it decays to 3He (1 neutron 2 protons). Think back to basic chemistry and you'll recall Hydrogen loves to bond, and Helium is a noble gas.

[/science] The gist of this is that our old stockpile is becoming less effective at blowing things up due to the stochastic (random) decay of tri

NIF itself isn't commercializeable, but a variant called HiPER definitely is. The only thing you *have* to destroy in either is the hohlraum (your "fuel bottle"). Commercialization requires low capital/operating costs and a high power production rate, which means a high repetition rate. NIF fails on both counts. HiPER inherently is an order of magnitude better on the former, and they're working on a high repetition-rate laser system for it even before the facility has started construction.

The reason its only ever 50 years away is because funding required to make it 0 years away is never accepted and projects are habitually underfunded and cut short before they reach their goals. Several scientific groups and individual scientists have said they'll bring it to us now if they get their X billion for funding. So far no government or company has had the good faith to grant the amount needed. There are prototypes from the 1950's which might have worked, but at the time cost'd some enormous amount. The deal is the science behind it is sound, but the investment sense is not for anyone with the ability to start it up. Its a little like building solar arrays in space, it will pay off, but in like 200 years.

The science is sound but the engineering isn't. The kind of problems that just the materials engineers have to cope with are stupendous for tokamak style high temp large scale reactors. The neutron bombardment of the structure holding the magnets makes it hard to figure out what material could stand up to the task. There are no known materials, last I checked in on this, that can do the job. So even if they get an energy sustaining reaction, they still have a bunch of engineering issues to solve which are v

The science is sound but the engineering isn't. The kind of problems that just the materials engineers have to cope with are stupendous for tokamak style high temp large scale reactors. The neutron bombardment of the structure holding the magnets makes it hard to figure out what material could stand up to the task. There are no known materials, last I checked in on this, that can do the job. So even if they get an energy sustaining reaction, they still have a bunch of engineering issues to solve which are very hard, if they want to build a commercial reactor that doesn't dissolve into dust after 5 years of operation. Much harder than the problems we solved for fission reactors..

Can't they just route the neutron pulse through the main deflector dish? And like, vent some drive plasma through the nacelles or something?

Unlike many technologies, fusion power requires a certain technological threshold to achieve, where various different technologies (possibly in the order of hundreds) finally reach the point where they are advanced enough to achieve breakeven or beyond. We need an electromagnetic containment system, a fuel-production system, monitoring and control, ignition (probably laser), even the materials the reactor is made of need to be of a certain kind. Many of these technologies we do not have, making fusion power more than simply requiring one specific breakthrough like many other technologies do.

It's a bit like how smartphones were developed. We needed not only better touchscreens, but better batteries, smaller computers, faster wireless systems, and more compact storage. Once a certain threshold was achieved, it became possible to build the modern smartphone. Before, things like them were possible, but a certain level of many technologies was required before it could really become practical.

The additional problem with fusion is not only to achieve breakeven, but to do so competitively versus other sources of power (specifically, coal). Coal is pretty cheap in terms of raw cost (the long-term consequences are much more expensive, but the investors can safely ignore most of those.) This is why fusion has been perpetually 50 years in the future: because so many things need to come together to make it practical that one single breakthrough, even if it is massive, simply won't be enough to make it practical. It is a technology we should pursue with tremendous effort, and which should one day pay off in one form or another, but it isn't a magic bullet and won't be for some time.

All of those things are also pointless until you get more energy out then you put into the laser in the first place. We have working Fusion reactors but none of them actually put out more energy then they take in. Unless you count an H-Bomb then it works just fine.

These people are idiots and deserve to be ridiculed and given a hard time as often as possible.

It's not nice to ridicule stupid people for their low intelligence. There is nothing they can do about that. It's like pointing and laughing at someone in a wheelchair for fighting with a flight of stairs. Also, we are all idiots some of the time, and there is nothing we can do about that. We might lower the rate of idiotic things we do by being careful, but we can never eliminate it completely, and there's a limit to how much effort it pays to use on being careful when momentary idiocy doesn't always have

We have working Fusion reactors but none of them actually put out more energy then they take in.

Sorry about being pedantic, but we don't care about the ratio of energy in to energy out, but instead the ratio of energy in to the usable energy out.

Your illustration of an H-bomb would have been informative if used correctly. Even an H-bomb produces more energy than it takes, but very little of the energy can be harnessed. In all fusion reactors today (including the H-bomb), the usable energy produced is less than the energy supplied.

To your point, how ever, you're ticking off all the steps of the process. You can't prove either fundamental theorems of calculus until you've got the real numbers 'constructed'. You can, how ever, walk up to calculus by tackling the intermediary steps one at a time. Part of your statement seems to be that it's an all or nothing proposition. Either we've got the energy generation, storage, and use all figured out at once and all together - or nothing c

It is a technology we should pursue with tremendous effort, and which should one day pay off in one form or another,

I disagree. Not everything is possible, and one can waste huge amounts of resources in things that will never happen. As it stands, there is no reason to believe fusion will ever happen in a halfway reasonable fashion within the next 500 years. Just like space elevators, warp drive, and so on.

There's a nice summary of the difficulties in this fine article, but unfortunately it is not for free:

Balaroth's point is that fusion takes a lot of different technologies working together in order to work well. This is true for a lot of technologies but fusion is an example where the total number of technologies is much higher than it is for lots of other technologies.

"The laser fusion idea uses pellets of fuel made of isotopes of hydrogen called deuterium and tritium. A number of lasers are fired at the pellets in order to compress the fuel to just hundredths of its starting size.

In the process, the hydrogen nuclei fuse to create helium and fast-moving subatomic particles called neutrons whose energy, in the form of heat, can be captured and used for the comparatively old-fashioned idea of driving a steam turbine."

That last line reads like the punchline of a (bad) joke. (It's also a testament to how useful water is.)

Anyway, there's huge potential revenues for solving this problem. I just hope a US company gets a share of the eventual windfall.

What makes this news worthy?

"We've done fusion at fairly high levels already. Even on Sunday night, we did the highest fusion yield that has ever been done."

"Dr Moses said that a single shot from the Nif's laser - the largest in the world - released a million billion neutrons and produced for a tiny fraction of a second more power than the world was consuming."

"Dr Moses said that a single shot from the Nif's laser - the largest in the world - released a million billion neutrons and produced for a tiny fraction of a second more power than the world was consuming."

The power is completely irrelevant. What matters is the time integral of the power, that is, the energy. Also, a million billion neutrons is only 10^15, at most a kilojoule of total energy (probably a lot less than that). To put that in perspective, the energy that a 1 kilogram hammer releases (at hi

There are now multiple different approaches to fusion research. Laser fusion looks promising although we don't have a really good understanding of how to efficiently extract energy from laser fusion. Magnetic containment fusion in the form of tokamaks is also still ongoing. There is an international group working now to build ITER which will be a very large tokamak which will be in France. http://en.wikipedia.org/wiki/ITER [wikipedia.org]. There are other ideas out there but unfortunately many of the more interesting ones are not receiving much funding. Laser fusion confines the plasma and crushes it with brief intense laser pulses while tokamaks confine the plasma using a torus of electromagnets. However, stellarators use a different form of magnetic confinement and might end up working but they are getting almost no funding.http://en.wikipedia.org/wiki/Stellarator [wikipedia.org]

The idea that we are always 50 years from fusion seems to be unfair. We've gotten much better at handling the basics. We can now consistently get fusion to occur with a variety of methods. The primary problems are doing so efficiently enough to get more energy out than we are putting in. We've made slow but steady progress at improving efficiency through a variety of methods. The development of so-called high temperature superconductors (that is able to superconduct a bit over the temperature at which nitrogen boils) in the 1970s has helped a lot. And the engineering issues really are immense. We've also sort of been spoiled by the previous success with fission power. The United States pored a massive amount of funding and resources into fission research from the beginning of the Manhattan project until a bit after World War 2. If fusion power was treated the same way we might be able to develop it quickly also.

There's another aspect about this sort of thing that is good news. The United States is steadily eroding its scientific and exploratory capability. We've retired the shuttle with no replacement. In the 1990s we canceled the Superconducting Super Collider. As a result when the LHC came online the US lost a lot of particle physicists who went over to Europe. The US particle physics has been in a state of decline since then. Most recently, the US is closing down the Tevatron, http://www.sciencenews.org/view/generic/id/68988/title/Tevatron_to_shut_down_in_September [sciencenews.org] which is the star US particle accelerator. While the energy levels of the Tevatron are less than the LHC the types and variety of collisions it does are sufficiently different such that having both of them is very much not redundant. And, the James Webb Telescope might be getting canceled, so it looks like cutting edge astronomy is another area the US is giving up on. If I had just been told that there was a Slashdot headline about laser fusion in the US I would have guessed that it would have been funding cuts for the NIR. The fact that organizations from elsewhere are actually joining suggests that the decline in US science might not be as bad as a pessimist might think. It might be reversible.

Different approaches are good in the long run and no approach should be abandoned (it's all good data) but to make something viable in the short term, you've got to reduce the number of efforts so that the money and the people can be put into one or two of the methods. Get it working with either, commercially, then do the same on two other methods, and so on.

High pressure short-term spectaculars aren't great for the science but they ARE great for the PR and therefore the public interest (and money). Give a

"We've also sort of been spoiled by the previous success with fission power. The United States pored a massive amount of funding and resources into fission research from the beginning of the Manhattan project until a bit after World War 2. If fusion power was treated the same way we might be able to develop it quickly also. "

Fission worked right away because neutrons are neutral electrically, but nuclei aren't. Fusion did work pretty soon too, but you can only do it with a fission weapon.

Fusion is probably going to take huge expensive and sophisticated facilities to produce an economically viable power reactor. To some point (not completely though) I think much of this has been just government works projects. On the other hand thorium nuclear reactors could be exploited for far less money and much quicker. Thorium is a fairly abundant element that does not have many of the negative properties which a plutonium or uranium based react would have. We have to do something to beef up the electrical grid. I read an article that said if 10% of the cars in the USA switched to electric, it would collapse the capacity of the grid. Besides, most electricity here is now generated by coal. Please look into the more promising technology of the liquid fluoride thorium reactor (LFTR).
http://en.wikipedia.org/wiki/LFTR [wikipedia.org]
http://www.youtube.com/watch?v=AZR0UKxNPh8 [youtube.com]
I'm not saying we should stop research on fusion, but we have to have a quickly viable alternative.

"I read an article that said if 10% of the cars in the USA switched to electric, it would collapse the capacity of the grid. "

Read something else...

"Since utilities have built enough power plants to provide electricity when people are operating their air conditioners at full blast, they have excess generating capacity during off-peak hours. As a result, according to an upcoming report from the Pacific Northwestern National Laboratory (PNNL), a Department of Energy lab, there is enough excess generating capa

funny other smarter countries in the U.S. are heavily investing and developing thorium (and other breeder technology) reactors. The first world will soon be those that have nuclear power, and the rest will be third world.

Thorium has similar problems to ordinary U/Pu fission. You still have fission product waste and still have the potential for release of large amounts of hazardous radioisotopes. It is fission, after all. These problems may well be manageable but they're manageable in conventional fission power stations too.

moving and positioning metal clad pellets at that *very slow* rate of feed is no big deal, bigger challenges have been met in advanced case-less and electromagnetic firearms design at over several hundred times the feed rate. The interior of the chamber and its feeding system will contain no water, and the chamber itself only need be surrounded by good heat sink with plumbing.

Put a whole bunch of smart and dedicated people together on the same project and they will work their ass off to solve that project. Along the way, they will develop (or spin off for development) a slew of other fantastic ideas.

I am sure there is a good reason, but why are we always fusing hydrogen? Why not heavier, easier to grab - move - focus elements? Like fusing Iron or something, it'll turn into something higher up the elements ladder. Because we can shuffle iron about with magnets quite easily, compared to hydrogen that isn't magnetic. Just some very fine iron dust into the big magnet thingy and hit it with all that pressure. Or if not Iron, something else.. Why always hydrogen?

You can fuse iron but you will have to put in more energy than you get out. Elements around iron and nickel are the most efficient way of storing protons and neutrons. So if you have larger elements like uranium you can get energy out by breaking them down. If you have really small elements you can get energy out by forming them into elements closer in size to iron. Moreover, fusing gets more difficult when you have larger elements because there are more protons in the nucleus so the strength of the positiv

I am sure there is a good reason, but why are we always fusing hydrogen? Why not heavier, easier to grab - move - focus elements? Like fusing Iron or something, it'll turn into something higher up the elements ladder. Because we can shuffle iron about with magnets quite easily, compared to hydrogen that isn't magnetic. Just some very fine iron dust into the big magnet thingy and hit it with all that pressure. Or if not Iron, something else.. Why always hydrogen?

Fusing the deteurium and tritium isotopes of hydroden is the easiest form there is. Next is deuterium-deuterium which has the advantage that of being naturally available. But, if you're having trouble getting DT fusion going, you will never get DD. Proton fusion, which is what the Sun mostly uses even harder and impractically slow. But that's why the Sun continues to shine. If it were made entirely of deterium and tritium, there would have been just one big bang and that would be it.

Yeah, The wit of the intellectually poor. If you cared to actually follow the developments, especially regarding the EROEI of fusion experiments, you'd see a constantly rising curve. We are at the point of breakeven, we could even surpass it, the remaining problems are largely material science optimizations. Plasma heating and containment is basically solved. But hey, rather spout a tired old meme - that'll get some herp derp from the retards that populate the internet today.

It also depends on what you call "breakeven"; it can be measured in many different ways. On the input side, you can consider only the energy which actually does useful work in the target, the total energy delivered to the target, the total energy consumed to power the delivery system, or the total energy consumed by the plant. On the output side, you can consider the raw total energy yielded by the fusion reactions, the total energy output by the whole fusion process (output of reactions minus whatever en

If someone asked that question 50 years ago, shouldn't we have it by now?

Not always.
For instance, in the early 80's the nuclear energy/plant specialists agreed at the time that they don't fully control the nuclear power, but they were absolutely convinced that it was only a matter of 20-30 years.
They were wrong.

People say that, and I understand the notion, but it really misses the point.

Fission power _always_ worked. At it's most basic level you could attach a thermocouple to radium and boom, power. Hell, just put enough enriched uranium (we had known about its fission properties) in one place and BOOM for sure. The only question was the actual engineering engineering effort to design a useful plant. Fusion is different. While it has long been possible to actually make it happen, getting it to produce a usefu

No one sounds dumber than an AC. The fact that you won't stand behind what you say drops 90% of your credibility before anyone even reads what you said.
Certainly, insulting people anonymously puts the 'C' in AC.

Not really.You will need to assume the Energy to product artificial gravity would be greater then the energy to make real gravity. So it will still probably take more energy then what is produced. Especially on the small scale energy production we need (Compared to a star).

You will need to assume the Energy to product artificial gravity would be greater then the energy to make real gravity

While discussing mythical technologies that probably will never exist we don't have to assume nothing.

But your comment doesn't really make sense because we can't make real gravity. Real gravity does exist and it costs us nothing so yea therefor obviously artificial gravity would cost us more than real gravity.

Now if you had said "You will need to assume the Energy to produce artificial gravity would be greater then the energy to make fusion." then what you said would make more sense. But I still don't se

Now if you had said "You will need to assume the Energy to produce artificial gravity would be greater then the energy to make fusion." then what you said would make more sense. But I still don't see why I would have to assume that.

I hate this attitude, which says that, "Because we don't have the holy grail yet, we haven't accomplished anything." The Q-factors on fusion reactions are many orders of magnitude better than we were getting even just a few decades ago. The amount of "unknown", while not eliminated, has been dramatically reduced, and on some paths, there's a pretty clear route to commercial viability. Inertial confinement, like NIF, in particular. Well, not exactly like NIF. The leading path for commercial viability of an inertial confinement system is HiPER [wikipedia.org], which uses a much smaller (and thus much lower capital/operating cost) compression pulse, and compensates by adding a heating pulse as well. It's calculated to get a Q-factor of about 100, which is well more than is needed for viable commercial power production. There's so much confidence that this could lead to viable commercial fusion power production that they're already starting to deal with some of the "commercialization" aspects, not just the raw physics aspects -- for example, a high repetition-rate laser system.

I had a chance to visit the ASDEX Upgrade experiment in Germany a couple of years ago. They showed a nice diagram of all the experiments done so far, plotting energy output to input versus time - constantly rising. The guy who led me around there was of the opinion that the remaining problems were mostly on the material side (of course that was his area of research). Plasma heating and confinement are pretty much ready - the problems lie in setting up the system for long term operation, and partly in heat t

the problems lie in setting up the system for long term operation, and partly in heat transfer.

This is the part of fusion research that I still don't get. It seems that all the (well-funded) ideas are all looking at an end-game that involves heating water to power a steam generator to produce electricity. Compared to all the technical issues they've been dealing with getting the fusion going, and the potential energy they are talking about generating, it seems somehow short-sighted and inefficient to still be focused on hooking the whole thing up to a bit of 18th century technology that will need a

Well, yeah - it does indeed sound quite counter-intuitive. But, then again, show me one piece of technology that works better for generating electricity from fusion - I just can't see anything. If no absolutely surprising breakthrough happens, I guess we are stuck by running Brayton or Rankine cycles.

Well there are no "working" fusion reactors at all, right now. But there are many ideas for converting fusion plasma directly into electrical power. I've heard electrostatic conversion (selective leakage and conversion), as well as compression-expansion techniques. Either one seems like they would be much more efficient, once you have that reaction going, than just letting the released particle bombard the reactor walls until it heats up enough to boil some water...

the problems lie in setting up the system for long term operation, and partly in heat transfer.

This is the part of fusion research that I still don't get. It seems that all the (well-funded) ideas are all looking at an end-game that involves heating water to power a steam generator to produce electricity. Compared to all the technical issues they've been dealing with getting the fusion going, and the potential energy they are talking about generating, it seems somehow short-sighted and inefficient to still be focused on hooking the whole thing up to a bit of 18th century technology that will need a huge fresh water supply to operate.

We've been making steam engines and turbines for a long time now and we've gotten very good at it: take 50% thermodynamic efficiency as a rough starting figure. Direct conversion requires fusion products that are charged particles, which come from only a few potential fuel sources (p+B11 is the most looked-at).

If we go with D+T or other neutron-bearing reactions then I think we'll be stuck with thermal cycles - i.e. steam/gas turbines - simply because there's no other way to extract energy from fast-moving,

What is needed is a plentiful supply of cold (relatively) water. So long as it doesn't mess up the condensers I don't expect cleanliness/saltiness is a deal-breaker; quantity is more important than quality.

Yea, I just meant "fresh" as in not seawater. Trust me, seawater is WAY to corrosive to use in pretty much ANYTHING that can get hot (that is, any kind of metal). If you don't believe me, try filling up your radiator with it and sell how long your cooling system lasts.

Interesting, I must read up on that. There's a nuclear station a few miles away from me, on the coast where I don't believe there's a river.

In any event the reason that we're still using heat engines is that the energy coming from reactors is heat. We can't generate electricity directly from neutrons, so there must always be an intermediary. We might replace the working fluid with something other than water (I've heard about mercury being used in the past) but we'll still be putting it in a turbine of some

In any event the reason that we're still using heat engines is that the energy coming from reactors is heat.

Not directly. The energy initially created is purely kinetic - the neutrons (or electrons, depending on the isotopes being fused) come flying off at a high rate of speed. The heat is generated by the particles slamming into the reactor / container wall, which is then dispersed across the surface, and eventually heats up by absorbing all that kinetic energy.

I'm guessing that there must be a way to use seawater to cool the condensers externally, because you're right, there are plenty of reactors close to c

I don't see how we need higher fields - as I said, plasma confinement is pretty much solved, and you do not even need 40T for it. You probably won't even need to continuously hold the plasma for productive operation - pulsed operation can work as well.

utter rubbish, you can't weaponize a fusion system designed for power generation, an electrical powered compression system that needs large buildings or many buildings isn't going into the volume of bucket for icbm launch nor into a briefcase.

utter rubbish, you can't weaponize a fusion system designed for power generation, an electrical powered compression system that needs large buildings or many buildings isn't going into the volume of bucket for icbm launch nor into a briefcase.

Nobody is trying to weaponize NIF. However, even the NIF website explains that one of their missions is to support stockpile stewardship: